Figure 2From: Effects of earplugs and eye masks on nocturnal sleep, melatonin and cortisol in a simulated intensive care unit environmentExample of sleep histograms from the same subject. Less rapid eye movement (REM) time, longer REM latency as exposure to recorded ICU noise and light. NL, recorded ICU noise and light exposure; NLEE, recorded ICU noise and light, subjects wore earplugs and eye masks.Back to article page